The invention relates to a cooling system for a liquid-cooled internal combustion engine including a radiator with a water box having an inlet for receiving coolant heated in the engine and an outlet for returning the cooled coolant to the engine, an expansion tank in communication with the radiator and a vehicle heater with a supply and a return line.
DE 34 33 370 C2 discloses a cooling system of a liquid cooled internal combustion engine including a radiator having a water box with coolant inlet and outlets disposed at the bottom of the radiator. An expansion tank is disposed at the top of the radiator in flow communication therewith. The inlet side of the radiator is in communication with a discharge nozzle for coolant heated in the engine and the discharge side is in communication with a coolant pump. Furthermore, the cooling system includes a vehicle heater with supply and return lines through which engine-heated coolant is circulated through the heater.
For general background information, further reference is made to patent publications DE 41 31 357 C1, DE 41 01 708 708 A1 and DE 28 27 022 A1.
The cooling circuits disclosed in these publications have the disadvantage that they are relatively complicated and require a relatively large number of various coolant flow and vent connections between the engine, the radiator and other heat exchangers (such as vehicle heater, oil cooler and auxiliary cooler). Furthermore, the relatively complicated arrangement of the coolant and vent lines is often the result of demands on the cooling circuit concerning the cooling of particular components. Furthermore, requirements concerning the venting of the cooling circuit particularly during vehicle operation and also, at the same time, important other aspects such as filling and draining of the cooling circuit with coolant must be taken into consideration such that they can be adequately satisfied.
It is the object of the present invention to provide a cooling system with a coolant flow control in such a way that the cooling system is relatively simple and inexpensive and also compact in design while all desirable properties concerning coolant control, venting, filling and draining are maintained.